Some links #3

Of my random meanderings around the Internet, I think the coolest thing I’ve seen this past week certainly has to be the Steampunk sequencer:

With that out of the way, here are some links:

What conclusions can we draw from Neanderthal DNA pt.2

ResearchBlogging.org4. Nuclear DNA: Forays into 3 billion base pairs

4.1 Before Vi-80

The Vindija-80 (Vi-80) specimen is an important find for geneticists: it yielded a minimally contaminated sample and provided those first steps into Neanderthal genomics.

Previously, attempts at retrieving ancient nuclear DNA sequences proved to be a notoriously difficult process, plagued with problems of degradation, contamination and chemical damage (Hofreiter et al., 2001). Researchers also need to contend with quantities of nuclear genome available: for every nuclear genome there are approximately several hundred mtDNAs (Green et al., 2008). The severity of these problems, especially contamination, is magnified through Neanderthal genetic similarity with humans (Green et al., 2006). This is troubling because nuclear DNA presents far less variability than mtDNA (Russell, 2002). As a result, huge stretches of nuclear sequences are required to find a significant number of polymorphisms (ibid). Such implications meant that discovering endogenous DNA sequences requires sifting through a large corpus of “[…] more than 70 Neanderthal bone and tooth samples from different sites in Europe and western Asia” (Green et al., 2006, pg. 331).

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Toadflax flowers are cool

Other than sound like a character from Bucky O’Hare, Toadflax (Linaria vulgaris) are fascinating plants for several reasons. Taking centre stage though is how this plant potentially offers another method of inheritance beyond genes. We’re now entering the slightly confusing world of epigenetics.

See, a particular species of these toadflax plants come in two distinct flavours: one consists of white, symmetrically arranged petals, whilst the other form is yellow and has five-pointed stars. Interestingly, this variation is not directly due to their DNA. Rather, these observed differences, which by the way are inherited by the offspring, are due to molecular caps attached to their DNA. As Carl Zimmer explains in his brilliant essay for the New York times:
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